Metallocenes, use in catalyst system for producing olefin polymers

ABSTRACT

A metallocene compound of formula (I): wherein M is zirconium, titanium and hafnium; X is a hydrogen atom, a halogen atom or a hydrocarbon radical; R 1  is a linear C 1 -C 20 -alkyl radical; R 2  is a hydrogen atom or hydrocarbon R 3 , R 4 , R 5 , R 6 , R 7 , and R 8 , are hydrogen atoms or hydrocarbon radicals, A is a sulphur (S) atom or an oxygen (O) atom; Q is a radical of formula (II), (III) or (IV) being bonded to the indenyl at the position indicated by the symbol *; (II), (III), (IV) wherein T 1  is a sulphur atom, an oxygen (O) atom or a NR; R 9 , R 10  and R 11  are hydrogen atoms or hydrocarbon radicals; T 2 , T 3 , T 4 , T 5 , and T 6  are carbon atoms (C) or nitrogen atoms (N); m 1 , m 2 , m 3 , m 4  and m 5  are 0 or 1; R 12 , R 13 , R 14 , R 15  and R 16  are hydrogen atoms or hydrocarbon radicals with the provisos that at least one of R 12 , R 13 , R 14 , R 15  and R 16  is different from hydrogen atoms, and that no more than two of T 2 , T 3 , T 4 , T 5  and T 6  are nitrogen atoms.

This application is the U.S. national phase of International ApplicationPCT/EP02/07093, filed Jun. 20, 2002.

The present invention relates to a new class of metallocene compounds,to catalysts based thereon and to a process carried out in the presenceof said catalysts for the preparation of polymers of alpha-olefins,particularly of propylene polymers. The present invention also relatesto the ligands for those metallocenes.

Products of propylene homopolymerization can have varying degrees ofcrystallinity. The type and amount of crystallinity is largely dependenton the microstructure of the polypropylene. Polypropylene havingpredominantly isotactic or syndiotactic structure is partiallycrystalline, while polypropylene having predominantly atactic structureis amorphous.

Metallocene catalysts have recently been used in the polymerizationreaction of olefins. Operating in the presence of these catalysts,polymers characterized by a narrow molecular weight distribution andhaving structural characteristics of interest have been obtained. Bypolymerizing propylene in the presence of metallocene catalysts,amorphous or highly crystalline polypropylenes can be obtained dependingon the metallocene used.

Certain metallocene catalysts are also known that can produce partiallycrystalline elastomeric polypropylene. International application WO95/25757, for instance, describes unbridged metallocene catalysts thatcan produce isotactic-atactic stereoblock polypropylenes havingelastomeric thermoplastic properties. Despite the homogeneity inmolecular weight distribution, the tacticity distribution of thesepolymers is not homogeneous. Moreover, the activity is low.

Recently, heterocyclic metallocene compounds have been used in thepolymerization of alpha-olefins. International application WO 98/22486discloses a class of metallocenes containing a cyclopentadienyl radicaldirectly coordinating the central metal atom, to which are fused one ormore rings containing at least one heteroatom. These metallocenes, incombination with a suitable cocatalyst, are used in the polymerizationof olefins such as propylene. The working examples relate to thepreparation of highly stereoregular polypropylene. More recently in WO01/47939 in the name of the same applicant a new class of heterocyclicmetallocene has been disclosed.

It would be desirable to provide a novel class of metallocenes which,when used in catalysts for the polymerization of olefins, in particularof propylene, are capable of yielding polymers endowed with highmolecular weights, high melting point, narrow molecular weightdistribution and a reduced degree of crystallinity. It would be mostdesirable to provide metallocene catalysts that can produce thosepolymers with high activity, such that the amount of catalyst remainingin the formed polymer is minimized.

A novel class of metallocene compounds has now been unexpectedly found,which achieves the above and other results.

According to a first aspect the present invention provides a metallocenecompound of formula (I):

wherein

M is selected from the group consisting of zirconium, titanium andhafnium; preferably M is zirconium or hafnium; more preferably M iszirconium;

X, same or different, is a hydrogen atom, a halogen atom, a R, OR, OR′O,OSO₂CF₃, OCOR, SR, NR₂ or PR₂ group, wherein the R substituents arelinear or branched, saturated or unsaturated C₁-C₂₀-alkyl,C₃-C₂₀-cycloalkyl, C₆-C₂₀-aryl, C₇-C₂₀-alkylaryl, C₇-C₂₀-arylakylradicals, optionally containing one or more heteroatoms belonging togroups 13-17 of the Periodic Table of the Elements; and the R′substituent is a divalent radical selected from the group consisting ofC₁-C₂₀-alkylidene, C₆-C₂₀-arylidene, C₇-C₂₀-alkylarylidene,C₇-C₂₀-arylalkylidene; preferably X is a halogen atom, a R, OR′ O or ORgroup; more preferably X is chlorine or methyl;

R¹ is a linear C₁-C₂₀-alkyl radical; preferably R¹ is methyl or ethyl;

R² is a hydrogen atom or a linear or branched, saturated or unsaturatedC₁-C₂₀-alkyl radical;

R³ and R⁴ same or different are hydrogen atoms or a linear or branched,saturated or unsaturated C₁-C₂₀-alkyl, C₃-C₂₀-cycloalkyl, C₆-C₂₀-aryl,C₇-C₂₀-alkylaryl, C₇-C₂₀-arylalkyl radicals, optionally containing oneor more heteroatoms belonging to groups 13-17 of the Periodic Table ofthe Elements, or they can form together a condensed saturated orunsaturated 5 or 6 membered ring, optionally containing one or moreheteroatoms belonging to groups 13-16 of the Periodic Table of theElements, said ring optionally bearing one or more substituents;preferably R³ and R⁴ are hydrogen atoms, methyl or they form a condensedsaturated or unsaturated 5 or 6 membered ring;

R⁵ and R⁶, same or different, are hydrogen atoms or a linear orbranched, saturated or unsaturated C₁-C₂₀-alkyl, C₃-C₂₀-cycloalkyl,C₆-C₂₀-aryl, C₇-C₂₀-alkylaryl, C₇-C₂₀-arylalkyl radicals, optionallycontaining one or more heteroatoms belonging to groups 13-17 of thePeriodic Table of the Elements; preferably R⁵ and R⁶ are a C₁-C₂₀-alkylradicals; more preferably they are methyl;

R⁷ and R⁸, same or different, are hydrogen atoms or a linear orbranched, saturated or unsaturated C₁-C₂₀-alkyl, C₃-C₂₀-cycloalkyl,C₆-C₂₀-aryl, C₇-C₂₀-alkylaryl, C₇-C₂₀-arylalkyl radicals, optionallycontaining one or more heteroatoms belonging to groups 13-17 of thePeriodic Table of the Elements; preferably R⁷ and R⁸ are C₁-C₂₀-alkyl orC₆-C₂₀-aryl radicals; more preferably they are methyl, or phenyl;

A, same or different, is a sulphur (S) atom or an oxygen (O) atom;preferably A is sulphur;

Q is a radical of formula (II), (III) or (IV) being bonded to theindenyl at the position marked with the symbol *;

wherein

T¹ is a sulphur (S) atom, an oxygen (O) atom or a NR group R beingdefined as above; preferably the group NR is N-methyl, N ethyl,N-tertbutyl or N-phenyl group; preferably T¹ is oxygen or sulphur; morepreferably T¹ is sulphur;

R⁹, R¹⁰ and R¹¹, same or different, are hydrogen atoms or a linear orbranched, saturated or unsaturated C₁-C₂₀-alkyl, C₃-C₂₀-cycloalkyl,C₆-C₂₀-aryl, C₇-C₂₀-alkylaryl, C₇-C₂₀-arylalkyl radicals, optionallycontaining one or more heteroatoms belonging to groups 13-17 of thePeriodic Table of the Elements; or R⁹ and R¹⁰ can form together acondensed saturated or unsaturated 5 or 6 membered ring, optionallycontaining one or more heteroatoms belonging to groups 13-16 of thePeriodic Table of the Elements, said ring optionally bearing one or moresubstituents;

preferably R¹¹ is a hydrogen atom, preferably R⁹ and R¹⁰ are a linear orbranched, saturated or unsaturated C₁-C₂₀-alkyl radical or they from acondensed saturated or unsaturated 5 or 6 membered ring, optionallycontaining one or more heteroatoms belonging to groups 13-16 of thePeriodic Table of the Elements, said ring optionally bearing one or moresubstituents; more preferably R⁹ and R¹⁰ form a condensed benzene ringoptionally bearing one or more substituents;

T², T³, T⁴, T⁵ and T⁶, same or different, are carbon atoms (C) ornitrogen atoms (N);

m¹, m², m³, m⁴ and m⁵ are 0 or 1; more precisely each of m¹, m², m³, m⁴and m⁵ is 0 when the correspondent T², T³, T⁴, T⁵ and T⁶ is a nitrogenatom and is 1 when the correspondent T², T³, T⁴, T⁵ and T⁶ is a carbonatom;

R¹², R¹³, R¹⁴, R¹⁵ and R¹⁶, same or different, are hydrogen atoms or alinear or branched, saturated or unsaturated C₁-C₂₀-alkyl,C₃-C₂₀-cycloalkyl, C₆-C₂₀-aryl, C₇-C₂₀-alkylaryl, C₇-C₂₀-arylalkylradicals, optionally containing one or more heteroatoms belonging togroups 13-17 of the Periodic Table of the Elements; or two vicinal R¹²,R¹³, R¹⁴, R¹⁵ can form together a condensed saturated or unsaturated 5or 6 membered ring, optionally containing one or more heteroatomsbelonging to groups 13-16 of the Periodic Table of the Elements, saidring optionally bearing one or more substituents; with the provisos thatat least one of R¹², R¹³, R¹⁴, R¹⁵ and R¹⁶ is different from hydrogenatom, and that no more than two of T², T³, T⁴, T⁵ and T⁶ are nitrogenatoms;

A preferred radical belonging to formula (IV) has formula (IVa) beingbonded to the indenyl at the position indicated by the symbol *:

wherein

R¹⁴ is described above with the proviso that it is different fromhydrogen atom; preferably

R¹⁴ is a branched, saturated or unsaturated C₁-C₂₀-alkyl or C₆-C₂₀-arylradical; more preferably

R¹⁴ is a phenyl group, optionally substituted with one or more alkylgroups, or a group of formula C(R¹⁷)₃ wherein R¹⁷, same or different, isa linear or branched, saturated or unsaturated C₁-C₂₀-alkyl radical;preferably R¹⁷ is methyl.

A further preferred radical belonging to formula (IV) has formula (IVb)being bonded to the indenyl at the position indicated by the symbol *:

wherein

R¹³ and R¹⁵, are described above with the proviso that they aredifferent from hydrogen atoms; preferably R¹³ and R¹⁵ are a branched,saturated or unsaturated C₁-C₂₀-alkyl or a CF₃ radical; more preferablythey are a group of formula C(R¹⁷)₃ wherein R¹⁷ has been describedabove;

R¹⁴ is a hydrogen atom or a R¹⁸ or OR¹⁸ group, wherein R¹⁸ is a linearor branched, saturated or unsaturated C₁-C₂₀-alkyl or C₆-C₂₀-arylradical optionally containing one or more heteroatoms belonging togroups 13-17 of the Periodic Table of the Elements; preferably R¹⁴ is ahydrogen atom or a OR¹⁸ group, preferably R¹⁸ is a linear or branched,saturated or unsaturated C₁-C₂₀-alkyl or C₆-C₂₀-aryl radical.

A further preferred radical belonging to formula (IV) has formula (IVc)being bonded to the indenyl at the position indicated by the symbol *:

wherein

R¹² and R¹⁵ are described above with the proviso that they are differentfrom hydrogen atoms; preferably R¹² and R¹⁵ are a linear, saturated orunsaturated C₁-C₂₀-alkyl radical; more preferably they are methyl.

A further preferred radical belonging to formula (IV) has formula (IVd)being bonded to the indenyl at the position indicated by the symbol *:

wherein

R¹² and R¹⁶ are described above with the proviso that they are differentfrom hydrogen atoms; preferably R¹² and R¹⁶ are a linear, saturated orunsaturated C₁-C₂₀-alkyl radicals; more preferably they are methyl.

A further preferred radical belonging to formula (IV) has formula (IVe)being bonded to the indenyl at the position indicated by the symbol *:

wherein

R¹² and R¹³ are described above with the proviso that they are differentfrom hydrogen atoms; preferably R¹² and R¹³ are a linear, saturated orunsaturated C₁-C₂₀-alkyl radical, or they can form a saturated orunsaturated condensed 5 or 6 membered ring optionally containing one ormore heteroatoms belonging to groups 13-16 of the Periodic Table of theElements, said ring optionally bearing one or more substituents; morepreferably R¹² and R¹³ form a saturated or unsaturated condensed 5 or 6membered ring optionally containing one or more heteroatoms belonging togroups 15-16 of the Periodic Table of the Elements such as a phenylring, a pentadiene ring or a naphtalene ring.

A further preferred radical belonging to formula (IV) has formula (IVf)being bonded to the indenyl at the position indicated by the symbol *:

wherein

R¹³, R¹⁴, R¹⁵ and R¹⁶ are described as above with the proviso that atleast one among R¹³, R¹⁴, R¹⁵ and R¹⁶ is different from a hydrogen atom;preferably R¹⁵ and R¹⁶ are hydrogen atoms; preferably R¹³ and R¹⁴ are alinear or branched, saturated or unsaturated C₁-C₂₀-alkyl radical, orthey form a saturated or unsaturated condensed 5 or 6 membered ringoptionally containing one or more heteroatoms belonging to groups 13-16of the Periodic Table of the Elements, said ring optionally bearing oneor more substituents; more preferably R¹³ and R¹⁴ form a saturated orunsaturated condensed 5 or 6 membered ring optionally containing one ormore heteroatoms belonging to groups 15-16 of the Periodic Table of theElements.

Preferably the metallocene compounds of formula (I) have formula (Ia) or(Ib):

wherein M, X, R¹, R⁵, R⁶, R⁷, R⁸, A and Q have been described above; R²is a linear or branched, saturated or unsaturated C₁-C₂₀-alkyl radical;preferably R² is methyl;

R³ and R⁴ form together a condensed saturated 5 or 6 membered aliphaticring;

Non limitative examples of compounds of formula (I) are:

wherein W is methyl or ethyl; as well as the corresponding zirconiumdimethyl complexes;

A further object of the present invention is a ligand of formula (V)that can be suitable used as intermediate for the preparation ofmetallocenes of formula (I).

and its double bond isomer;

wherein R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, A and Q have been describedabove.

This ligand can be prepared according to a process comprising thefollowing steps:

-   -   a) contacting a compound of the formula (VI)

-   -    with a base selected from the group consisting of metallic        sodium and potassium, sodium and potassium hydroxide,        organolithium compound and an organomagnesium compound wherein        the molar ratio between the compound of the formula (VI) and        said base is at least 1:1    -   b) contacting the anionic compounds obtained from step a) with a        compound of formula (VII):

-   -    wherein Y is a halogen radical selected from the group        consisting of chloride, bromide and iodide, preferably chlorine        and bromine.

An alternative process for preparing the ligand of formula (V) comprisesthe following steps:

-   -   a) contacting a compound of the formula (VIII)

-   -    with a base selected from the group consisting of metallic        sodium and potassium, sodium and potassium hydroxide, an        organolithium compound and an organomagnesium compound, wherein        the molar ratio between the compound of the formula (VIII) and        said base is at least 1:1;    -   b) contacting the anionic compounds obtained from step a) with a        compound of formula (IX):

-   -    wherein Y is a halogen radical selected from the group        consisting of chloride, bromide and iodide, preferably chlorine        and bromine.

The base used in step a) of both processes is preferably methyllithiumor n-butyllithium. All the reactions are carried out in aproticsolvents. Non limiting examples of aprotic solvents suitable for theabove reported processes are tetrahydrofurane, dimethoxyethane,diethylether, toluene, dichloromethane pentane, hexane and benzene.

During the whole processes, the temperature is generally kept between−100° C. and 80° C., preferably between −20° C. and 40° C.

Compounds of formula (VI), (VII), (VIII) and (IX) are known in the art.In particular compounds of formula (VI) and (IX) can be preparedaccording to the process described in PCT/EP00/13191 or EP 01201821.4.Compounds of formula (VII) and (VIII) can be prepared a described in WO9840331, WO 9840419 and WO 9840416.

Compounds of formula (V) can be suitable used as intermediates for thepreparation of metallocenes of formula (I).

Therefore, a process for the preparation of a metallocene compound offormula (I), comprises the steps of contacting the ligand of formula(V), with a compound capable of forming the corresponding dianioniccompound and thereafter with a compound of general formula MX₄, whereinM and X are defined as above.

The compound able to form said corresponding dianionic compound isselected from the group consisting of hydroxides of alkali- andalkaline-earth metals, metallic sodium and potassium, organometalliclithium salts or organomagnesium compounds (Grignard reagent).Preferably, the compound able to form said corresponding dianioniccompound is hexillithium, butylithium or methylithium.

Non-limiting examples of compounds of formula MX₄ are titanium,zirconium and hafnium tetrachloride.

More specifically, the ligand of formula (V) is dissolved in a polaraprotic solvent and to the obtained solution is added a solution of anorganolithium compound in an apolar solvent. The thus obtained anioniccompound is optionally separated, dissolved or suspended in a polaraprotic solvent and thereafter added to a suspension of the compound MX₄in a polar aprotic solvent. At the end of the reaction, the solidproduct obtained is separated from the reaction mixture by techniquescommonly used in the state of the art such as filtration orrecrystallization. Non limiting examples of polar aprotic solventssuitable for the above reported processes are tetrahydrofurane,dimethoxyethane, diethylether and dichloromethane. Non limiting examplesof apolar solvents suitable for the above process are pentane, hexane,benzene and toluene.

Throughout the process, the temperature is generally kept between −100°C. and 80° C., preferably between −20° C. and 40° C.

An alternative process for preparing the compounds of formula (I)wherein at least one X is halogen is described in EP 01201327.2.

In the case in which at least one substituent X in the metallocenecompound of the formula (I) is different from halogen an alternativeprocess for preparing it consists in preparing the dihalogen derivative,i.e. the complex wherein both X substituents are halogen, and thensubstituting the halogen atoms with the appropriate X groups by themethods generally known in the art. For example, if the desiredsubstituents X are alkyl groups, the metallocenes can be made byreaction with organomagnesium compound (Grignard reagents) or withalkyllithium compounds. General methods for substituting X withsubstituents other than halogen such as sulfur, phosphorus, oxygen, etc.are described in Chem. Rev. 1994, 94, 1661-1717, and the citedreferences therein. An alternative process for preparing the compoundsof formula (I) wherein at least one X is alkyl is described in WO99/36427.

Another object of the present invention is a catalyst for thepolymerization of alpha-olefins obtainable by contacting:

-   -   a) a metallocene compound of formula (I):

-   -    wherein M, X, R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, A and Q have been        described above;    -   b) an alumoxane or a compound able to form an alkylmetallocene        cation; and    -   c) optionally an organo aluminum compound.

Alumoxanes used as component b) can be obtained by reacting water withan organo-aluminium compound of formula H_(j)AlU_(3-j) orH_(j)Al₂U_(6-j), where U substituents, same or different, are hydrogenatoms, C₁-C₂₀-alkyl, C₃-C₂₀-cyclalkyl, C₆-C₂₀-aryl, C₇-C₂₀-alkylaryl orC₇-C₂₀-arylalkyl radical, optionally containing silicon or germaniumatoms with the proviso that at least one U is different from halogen,and j ranges from 0 to 1, being also a non-integer number. In thisreaction the molar ratio of Al/water is preferably comprised between 1:1and 100:1.

The molar ratio between aluminium and the metal of the metallocene iscomprised between about 10:1 and about 20000:1, and more preferablybetween about 100:1 and about 5000:1.

The alumoxanes used in the catalyst according to the invention areconsidered to be linear, branched or cyclic compounds containing atleast one group of the type:

wherein the substituents U, same or different, are described above.

In particular, alumoxanes of the formula:

can be used in the case of linear compounds, wherein n¹ is 0 or aninteger from 1 to 40 and the substituents U are defined as above, oralumoxanes of the formula:

can be used in the case of cyclic compounds, wherein n² is an integerfrom 2 to 40 and the U substituents are defined as above.

Examples of alumoxanes suitable for use according to the presentinvention are methylalumoxane (MAO), tetra-(isobutyl)alumoxane (TIBAO),tetra-(2,4,4-trimethyl-pentyl)alumoxane (TIOAO),tetra-(2,3-dimethylbutyl)alumoxane (TDMBAO) andtetra-(2,3,3-trimethylbutyl)alumoxane (TTMBAO).

Particularly interesting cocatalysts are those described in WO 99/21899and in PCT/EP00/09111 in which the alkyl and aryl groups have specificbranched patterns.

Non-limiting examples of aluminium compounds according to said PCTapplications are: tris(2,3,3-trimethyl-butyl)aluminium,tris(2,3-dimethyl-hexyl)aluminium, tris(2,3-dimethyl-butyl)aluminium,tris(2,3-dimethyl-pentyl)aluminium, tris(2,3-dimethyl-heptyl)aluminium,tris(2-methyl-3-ethyl-pentyl)aluminium,tris(2-methyl-3-ethyl-hexyl)aluminium,tris(2-methyl-3-ethyl-heptyl)aluminium,tris(2-methyl-3-propyl-hexyl)aluminium,tris(2-ethyl-3-methyl-butyl)aluminium,tris(2-ethyl-3-methyl-pentyl)aluminium,tris(2,3-diethyl-pentyl)aluminium,tris(2-propyl-3-methyl-butyl)aluminium,tris(2-isopropyl-3-methyl-butyl)aluminium,tris(2-isobutyl-3-methyl-pentyl)aluminium,tris(2,3,3-trimethyl-pentyl)aluminium,tris(2,3,3-trimethyl-hexyl)aluminium,tris(2-ethyl-3,3-dimethyl-butyl)aluminium,tris(2-ethyl-3,3-dimethyl-pentyl)aluminium,tris(2-isopropyl-3,3-dimethyl-butyl)aluminium,tris(2-trimethylsilyl-propyl)aluminium,tris(2-methyl-3-phenyl-butyl)aluminium,tris(2-ethyl-3-phenyl-butyl)aluminium,tris(2,3-dimethyl-3-phenyl-butyl)aluminium,tris(2-phenyl-propyl)aluminium,tris[2-(4-fluoro-phenyl)-propyl]aluminium,tris[2-(4-chloro-phenyl)-propyl]aluminium,tris[2-(3-isopropyl-phenyl)-propyl]aluminium,tris(2-phenyl-butyl)aluminium, tris(3-methyl-2-phenyl-butyl)aluminium,tris(2-phenyl-pentyl)aluminium,tris[2-(pentafluorophenyl)-propyl]aluminium,tris[2,2-diphenyl-ethyl]aluminium andtris[2-phenyl-2-methyl-propyl]aluminium, as well as the correspondingcompounds wherein one of the hydrocarbyl groups is replaced with ahydrogen atom, and those wherein one or two of the hydrocarbyl groupsare replaced with an isobutyl group.

Amongst the above aluminium compounds, trimethylaluminium (TMA),triisobutylaluminium (TIBAL), tris(2,4,4-trimethyl-pentyl)aluminium(TIOA), tris(2,3-dimethylbutyl)aluminium (TDMBA) andtris(2,3,3-trimethylbutyl)aluminium (TTUMBA) are preferred.

Non-limiting examples of compounds able to form an alkylmetallocenecation are compounds of formula D⁺E⁻, wherein D⁺ is a Brøonsted acid,able to donate a proton and to react irreversibly with a substituent Xof the metallocene of formula (D and E⁻ is a compatible anion, which isable to stabilize the active catalytic species originating from thereaction of the two compounds, and which is sufficiently labile to beable to be removed by an olefinic monomer. Preferably, the anion E⁻comprises of one or more boron atoms. More preferably, the anion E⁻ isan anion of the formula BAr₄ ⁽⁻⁾, wherein the substituents Ar which canbe identical or different are aryl radicals such as phenyl,pentafluorophenyl or bis(trifluoromethyl)phenyl.Tetrakis-pentafluorophenyl borate is particularly preferred examples ofthese compounds are described in WO 91/02012. Moreover, compounds of theformula BAr₃ can conveniently be used. Compounds of this type aredescribed, for example, in the published International patentapplication WO 92/00333. Other examples of compounds able to form analkylmetallocene cation are compounds of formula BAR₃P wherein P is asubstituted or unsubstituted pyrrol radicals. These compounds aredescribed in PCT/EP01/01467. Compounds containing boron atoms can beconveniently supported according to the description of DE-A-19962814 andDE-A-19962910. All these compounds containing boron atoms can be used ina molar ratio between boron and the metal of the metallocene comprisedbetween about 1:1 and about 10:1; preferably 1:1 and 2.1; morepreferably about 1:1.

Non limiting examples of compounds of formula D⁺E⁻ are:

-   Triethylammoniumtetra(phenyl)borate,-   Tributylammoniumtetra(phenyl)borate,-   Trimethylammoniumtetra(tolyl)borate,-   Tributylammoniumtetra(tolyl)borate,-   Tributylammoniumtetra(pentafluorophenyl)borate,-   Tributylammoniumtetra(pentafluorophenyl)aluminate,-   Tripropylammoniumtetra(dimethylphenyl)borate,-   Tributylammoniumtetra(trifluoromethylphenyl)borate,-   Tributylammoniumtetra(4-fluorophenyl)borate,-   N,N-Dimethylani liniumtetra(phenyl)borate,-   N,N-Diethylaniliniumtetra(phenyl)borate,-   N,N-Dimethylaniliniumtetrakis(pentafluorophenyl)boratee,-   N,N-Dimethylaniliniumtetrakis(pentafluorophenyl)aluminate,-   Di(propyl)ammoniumtetrakis(pentafluorophenyl)borate,-   Di(cyclohexyl)ammoniumtetrakis(pentafluorophenyl)borate,-   Triphenylphosphoniumtetrakis(phenyl)borate,-   Triethylphosphoniumtetrakis(phenyl)borate,-   Diphenylphosphoniumtetrakis(phenyl)borate,-   Tri(methylphenyl)phosphoniumtetrakis(phenyl)borate,-   Tri(dimethylphenyl)phosphoniumtetrakis(phenyl)borate,-   Triphenylcarbeniumtetrakis(pentafluorophenyl)borate,-   Triphenylcarbeniumtetrakis(pentafluorophenyl)aluminate,-   Triphenylcarbeniumtetrakis(phenyl)aluminate,-   Ferroceniumtetrakis(pentafluorophenyl)borate,-   Ferroceniumtetrakis(pentafluorophenyl)aluminate.-   Triphenylcarbeniumtetrakis(pentafluorophenyl)borate,-   N,N-Dimethylaniliniumtetrakis(pentafluorophenyl)borate.

Organic aluminum compounds used as compound c) are those of formulaH_(j)AlU_(3-j) or H_(j)Al₂U_(6-j) described above.

The catalysts of the present invention can also be supported on an inertcarrier. This is achieved by depositing the metallocene compound a) orthe product of the reaction thereof with the component b), or thecomponent b) and then the metallocene compound a) on an inert supportsuch as, for example, silica, alumina, Al—Si, Al—Mg mixed oxides,magnesium halides, styrene/divinylbenzene copolymers, polyethylene orpolypropylene. The supportation process is carried out in an inertsolvent such as hydrocarbon for example toluene, hexane, pentane orpropane and at a temperature ranging from 0° C. to 100° C., preferablythe process is carried out at a temperature ranging from 20° C. to 80°C.

A suitable class of supports which can be used is that constituted byporous organic supports functionalized with groups having activehydrogen atoms. Particularly suitable are those in which the organicsupport is a partially crosslinked styrene polymer. Supports of thistype are described in European application EP-633272.

Another class of inert supports particularly suitable for use accordingto the invention is that of polyolefin porous prepolymers, particularlypolyethylene.

A further suitable class of inert supports for use according to theinvention is that of porous magnesium halides such as those described inInternational application WO 95/32995.

The solid compound thus obtained, in combination with the furtheraddition of the alkylaluminium compound either as such or prereactedwith water if necessary, can be usefully employed in the gas-phasepolymerization.

Another object of the present invention is a process for polymerizingone or more alpha-olefins of formula CH₂═CHZ, wherein Z is hydrogen or aC₁-C₂₀ alkyl group, comprising the step of contacting underpolymerization conditions one or more of said alpha-olefins with acatalyst system obtainable by contacting:

-   -   a) a metallocene compound of formula (I):

-   -    wherein M, X, R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, A and Q have been        described above;    -   b) one or more alumoxanes or compounds able to form an        alkylmetallocene cation; and    -   c) optionally an organo aluminum compound.

The process for the polymerization of olefins according to the inventioncan be carried out in the liquid phase in the presence or absence of aninert hydrocarbon solvent, or in the gas phase. The hydrocarbon solventcan either be aromatic such as toluene, or aliphatic such as propane,hexane, heptane, isobutane or cyclohexane.

The polymerization temperature is generally comprised between −100° C.and +100° C. and, particularly between 10° C. and +90° C. Thepolymerization pressure is generally comprised between 0.5 and 100 bar.

The lower the polymerization temperature, the higher are the resultingmolecular weights of the polymers obtained.

The polymerization yields depend on the purity of the metallocenecompound of the catalyst. The metallocene compounds obtained by theprocess of the invention can therefore be used as such or can besubjected to purification treatments.

The components of the catalyst can be brought into contact with eachother before the polymerization. The pre-contact concentrations aregenerally between 0.1 and 10⁻⁸ mol/l for the metallocene component a),while they are generally between 2 and 10⁻⁸ mol/l for the component b).The pre-contact is generally effected in the presence of a hydrocarbonsolvent and, if appropriate, of small quantities of monomer. In thepre-contact it is also possible to use a non-polymerizable olefin suchas isobutene, 2-butene and the like.

Further, the molecular weights of the polymer obtained, are distributedover relatively limited ranges. The molecular weight distribution can berepresented by the ratio Mw/Mn which, for the present polymers, isgenerally lower than 4, preferably lower than 3.5 and, more preferably,lower than 3.

The molecular weight distribution can be varied by using mixtures ofdifferent metallocene compounds or by carrying out the polymerization inseveral stages which differ as to the polymerization temperature and/orthe concentrations of the molecular weight regulators and/or themonomers concentration. Moreover by carrying out the polymerizationprocess by using a combination of two different metallocene compounds offormula (I) a polymer endowed with a broad melting is produced.

By using the metallocene compounds of formula (I) it is possible toobtain polymers, especially propylene polymers endowed with a highermolecular weight than the polymer obtained in the same conditions withthe catalyst of the prior art. In particular the good balance betweenisotacticity and molecular weight makes the metallocene compounds offormula (I) useful for application on industrial scale.

The process according to the present invention is also suitable forobtaining homo or copolymers of ethylene or higher alpha-olefins such aspropylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene,1-decene, 1-dodecene, styrene, 1,5-hexadiene and 1,7-octadiene.Preferred monomers are ethylene, 1-butene or propylene.

The propylene polymers described above are endowed with good balancebetween optical and mechanical properties.

In the case of propylene copolymers the molar content of propylenederived units is generally higher than 20%, and preferably it iscomprised between 50% and 99%. Preferred comonomers are ethylene or1-butene.

In the case of ethylene copolymers the molar content of ethylene derivedunits is generally higher than 20%, and preferably it is comprisedbetween 50% and 99%. preferred monomers are propylene, 1-butene,1-hexene, 1-octene.

The copolymers according to the invention can also contain units derivedfrom polyenes. The content of polyene derived units, if any, ispreferably comprised between 0% and 30 mol % and, more preferablybetween 0% and 20 mol %.

The polyenes that can be used as comonomers in the copolymers accordingto the present invention are included in the following classes:

-   -   non-conjugated diolefins able to cyclopolymerize such as, for        example, 1,5-hexadiene, 1-6-heptadiene, 2-methyl-1,5-hexadiene;    -   dienes capable of giving unsaturated monomeric units, in        particular conjugated dienes such as, for example, butadiene and        isoprene, and linear non-conjugated dienes, such as, for        example, trans 1,4-hexadiene, cis 1,4-hexadiene,        6-methyl-1,5-heptadiene, 3,7-dimethyl-1,6-octadiene,        11-methyl-1,10-dodecadiene, and cyclic non-conjugated dienes        such as 5-ethylidene-2-norbornene.

The following examples are given for illustrative purpose and do notintend to limit the invention.

EXAMPLES

General Procedures.

All operations were performed under nitrogen by using conventionalSchlenk-line techniques. Solvents were purified by degassing with N₂ andpassing over activated (8 hours, N₂ purge, 300° C.) Al₂O₃, and storedunder nitrogen. Me₂SiCl₂ (Aldrich), n-BuLi (Aldrich) and HexLi (Aldrich)were used as received.

The proton spectra of precursors, ligands and metallocenes were obtainedon a Bruker DPX 200 spectrometer operating in the Fourier transform modeat room temperature at 200.13 MHz. The samples were dissolved in CDCl₃or CD₂Cl₂: CDCl₃ (Aldrich, 99.8 atom % D) was stored over molecularsieves (4-5 Å), while CD₂Cl₂ (Aldrich, 99.8 atom % D) was used asreceived. Preparation of the samples was carried out under nitrogenusing standard inert atmosphere techniques. The residual peak of CHCl₃or CHDCl₂ in the ¹H spectra (7.25 ppm and 5.35 ppm, respectively) wasused as a reference.

Proton spectra were acquired with a 15° pulse and 2 seconds of delaybetween pulses; 32 transients were stored for each spectrum.

GC-MS analyses were carried out on a HP 5890—serie 2 gas-chromatographand a HP 5989B quadrupole mass spectrometer.

Polymer Analysis.

The carbon spectra of the polymers were obtained using a Bruker DPX 400spectrometer operating in the Fourier transform mode at 120° C. and100.61 MHz. The samples were dissolved in C₂D₂Cl₄. As a reference, thepeak of the mmmm pentad in the ¹³C spectra (21.8 ppm) was used.

The carbon spectra were acquired with a 90° pulse and 12 seconds (15seconds for ethylene based polymers) of delay between pulses and CPD(waltz 16) to remove ¹H-¹³C couplings. About 3000 transients were storedfor each spectrum.

The intrinsic viscosity (I.V.) was measured in tetrahydronaphthalene(THN) at 135° C.

The melting points and heat of fusion of the polymers (T_(m)) weremeasured by Differential Scanning Calorimetry (DSC) on a Perkin ElmerDSC-7 instruments, according to the standard method, on 5-10 mg samplessealed into aluminum pans and heated at 200° C. with a heating rate of10° C./minute. The sample was kept at 200° C. for 2 minutes, then cooledto 25° C. at 10° C./minute, then kept 2 minutes at 25° C., and thenheated again up to 200° C. at 10° C./min. The peak temperature of thesecond melting was assumed as melting temperature (T_(m)) and the areaas global melting enthalpy (ΔH_(f)).

Example 1 Synthesis ofdimethylsily{(2-methyl-4-(4-tert-butylphenyl)-1-indenyl)-7-(2,5-dimethyl-cyclopenta[1,2-b:4,3-b′]-dithiophene)}zirconiumdichloride [C-1] Synthesis ofchloro(2-methyl-4-tert-butylphenyl-1-indenyl)dimethylsilane

A 2.5 M n-BuLi solution in hexane (4.99 mL, 12.48 mmol,n-BuLi:2-Me-4-(4′-t-BuPh)-1-Ind=1.05:1) was added dropwise at 0° C. to asuspension of 3.12 g of 2-methyl-4-(4′-tert-butylphenyl)-1-indene(MW=262.39, 11.89 mmol) in 20 mL of Et₂O. At the end of the addition,the resulting yellow-orange solution was allowed to warm up to roomtemperature and stirred for 30 min. Then a solution of Me₂SiCl₂ (99%,1.50 mL, d=1.064, MW=129.06, 12.24 mmol,Me₂SiCl₂/2-Me-4-(4′-t-BuPh)IndLi=1.02:1) in 10 mL of Et₂O was added at0° C. to the lithium salt solution, previously cooled to 0° C. Thereaction mixture was allowed to warm up to room temperature and stirredfor 1 h with final formation of a yellow suspension. The solvents wereremoved in vacuo and the residue extracted with 50 mL of toluene toremove the LiCl. The filtrate was brought to dryness in vacuo at 40° C.to give an orange oil as product (4.17 g). Yield=83.9%. Punrity (by ¹HNMR)=84.9 wt %. About 11% (by ¹H NMR) ofbis(2-methyl-4-(4′-tert-butylphenyl)-1-indenyl)dimethylsilane was alsopresent as by-product.

¹H NMR (δ, ppm, CDCl₃): 0.22 (s, 3H, Si—CH₃); 0.47 (s, 3H, Si—CH₃); 1.43(s, 9H, t-Bu); 2.31 (d, 3H, J=0.98 Hz, CH₃); 3.69 (s, 1H, CH); 6.88 (s,1H, Cp-H); 7.17-7.57 (m, 7H, Ar). m/z (%): 356 (40) [M⁺+2], 355 (31)[M⁺+1], 354 (100) [M⁺], 341 (27), 340 (20), 339 (67), 260 (19), 215(24), 203 (28), 95 (36), 93 (98), 57 (34).

Synthesis of1-(2-methyl-4-(4′-tert-butylphenylindenyl)-7-(2,5-dimethyl-cyclopenta[1,2-b:4,3-b′]-dithiophene)dimethylsilane

A 2.5 M solution of n-BuLi in hexane (4.11 mL, 10.28 mmol) was addeddropwise at 0° C. to a suspension of 2.06 g of2,5-dimethyl-7H-cyclopenta[1,2-b:4,3-b′]-dithiophene (Mw=206.32, 9.98mmol, n-BuLi: MeTh₂Cp=1.03:1) in 25 mL of Et₂O. The resulting brownsolution was stirred at 0° C. for 30 min and then a solution of 4.17 gof chloro[2-methyl-4-(4′-tert-butylphenyl)-1-indenyl]dimethylsilane(purity by ¹H NMR=84.9 wt %, Mw=354.99, 9.97 mmol,2-Me-4-(4′-t-BuPh)IndSiMe₂Cl:MeTh₂Cp=1:1) in 15 mL of Et₂O was added atthe same temperature. The reaction mixture was then allowed to warm upto room temperature and stirred for 30 min with final formation of agreen suspension. The solvents were evaporated under reduced pressureand the residue was extracted with 50 mL of toluene. The extract wasdried in vacuo to give 5.82 g of a brown oil, which resulted to be thedesired product by ¹H-NMR spectroscopy (purity by ¹H-NMR=89.8 wt %,yield=99.8%).

¹H NMR (δ, ppm, CD₂Cl₂): −0.30 (s, 3H, Si—CH₃); −0.29 (s, 3H, Si—CH₃);1.42 (s, 9H, t-Bu); 2.28 (d, 3H, J=0.98 Hz, CH₃); 2.59 (bs, 3H, CH₃);2.61 (bs, 3H, CH₃); 3.98 (s, 1H, CH); 4.09 (s, 1H, CH); 6.87 (m, 1H,Cp-H); 6.92 (q, 1H, J=1.17 Hz, CH); 6.94 (q, 1H, J=1.17 Hz, CH);7.15-7.54 (m, 7H, Ar). m/z (%): 524 (4) [M⁺], 265 (11), 264 (24), 263(100), 235 (13), 57 (20).

Synthesis ofdimethylsilyl{(2-methyl-4-(4′-tert-butylphenyl)-1-indenyl)-7-(2,5-dimethyl-cyclopental[1,2-b:4,3-b′]-dithiophene)}zirconiumdichloride

A 2.5 M solution of n-BuLi in hexane (8.16 mL, 20.40 mmol) was addeddropwise at 0° C. to a brick red solution of 5.82 g1-[2-methyl-4-(4′-tert-butylphenyl)indenyl]-7-(2,5-dimethyl-cyclopenta[1,2-b:4,3-b′]-dithiophene)dimethylsilane(purity by ¹H-NMR=89.8 wt %, Mw=524.85, 9.96 mmol, n-BuLi:ligand=2.05:1)in 35 mL of Et₂O. The resulting dark brown solution was stirred for 30min at room temperature and then a suspension of 2.32 g of ZrCl₄(Mw=233.03, 9.96 mmol, ZrCl₄:ligand=1:1) in 12 mL of toluene was addedat the same temperature. The reaction mixture was stirred at roomtemperature for 1 h and then the solvents were removed in vacuo. Theresidue was added of 60 mL of toluene, stirred for 30 min at roomtemperature and then filtered. The filtrate was eliminated, while theinsoluble in toluene was washed with CH₂Cl₂ and then dried to give anorange powder as product, which resulted to be the desired catalyst by¹H-NMR (5.4 g, yield with LiCl 79.2%).

An aliquot of this powder (1.48 g) was washed very quickly with 10 mL ofTHF: the residue, an orange powder (0.85 g), contained the targetcatalyst, while the filtrate (0.63 g) showed partial decomposition tothe starting ligand. The orange powder (0.85 g) was subsequently washedwith 10 mL of a mixture of isobutanol/toluene ca. 1/1 (v/v) to give,after drying, 0.69 g of the desired catalyst free from LiCl. Thefiltrate showed also in this case partial decomposition to the startingligand.

¹H NMR (δ, ppm, CDCl₃): 1.16 (s, 3H, Si—CH₃); 1.32 (s, 12H, t-Bu andSi—CH₃); 2.34 (bs, 3H, CH₃); 2.41 (bs, 3H, CH₃); 2.59 (bs, 3H, CH₃);6.62 (bs, 1H, CH); 6.75 (bs, 1H, CH); 6.87-7.65 (m, 8H, Cp-H and Ar).

Example 2 Synthesis ofdimethylsilyl{(2-methyl-4-(3′,5′-di-tert-butylphenyl)-1-indenyl)-7-(2,5-dimethyl-cyclopental[1,2-b:4,3-b′]-dithiophene)}zirconiumdichloride [C-2] Synthesis of1-(2-methyl-4-(3′,5′-di-tert-butylphenylindenyl)-7-(2,5-dimethyl-cyclopental[1,2-b:4,3-b′]-dithiophene)dimethylsilane

A 2.3 M HexilLithium(HexLi) solution in hexane (6.40 mL, 14.72 mmol) wasadded dropwise at 0° C. to a suspension of 2.90 g of2,5-dimethyl-7H-cyclopenta[1,2-b:4,3-b′]-dithiophene (Mw=206.32, 14.06mmol, HexLi: MeTh₂Cp=1.05:1) in 25 mL of Et₂O. The resulting brownsolution was stirred at 0° C. for 1 h and then a solution of 5.76 g ofchloro[2-methyl-4-(3′,5′-di-tert-butylphenyl)-1-indenyl]dimethylsilane(J. Schulte sample, Mw=411.11, 14.01 mmol,2-Me-4-(3′,5′-di-t-BuPh)IndSiMe₂Cl:MeTh₂Cp=1:1) in 20 mL of Et₂O wasadded at the same temperature. Because of the low solubility of theproduct in the ether/hexane mixture, 5 mL of THF were added. Thereaction mixture was then allowed to warm up to room temperature andstirred for 16 h with final formation of a brown suspension. Thesolvents were evaporated under reduced pressure and the residue wasextracted with 20 mL of toluene. The extract was dried in vacuo to give7.66 g of an orange sticky solid, which resulted to be the desiredproduct by ¹H-NMR spectroscopy (yield=94.1%, purity ca. 90% wt). Theligand was used as such in the next step without further purification.

¹H NMR (δ, ppm, CD₂Cl₂): −0.24 (s, 3H, Si—CH₃); −0.26 (s, 3H, Si—CH₃);1.45 (s, 18H, t-Bu); 2.30 (s, 3H, CH₃); 2.60 (bs, 3H, CH₃); 2.62 (bs,3H, CH₃); 4.00 (bs, 1H, CH); 4.06 (bs, 1H, CH); 6.86 (bs, 1H, Cp-H);6.94 (q, 1H, J=1.17 Hz, CH); 6.95 (q, 1H, J=1.17 Hz, CH); 6.95 (q, 1H,J=1.17 Hz, CH); 7.18-7.50 (m, 6H, Ar). m/z (%): 581 (1) [M⁺+1], 376(25), 319 (14), 265 (14), 264 (22), 263 (100), 248 (12), 235 (22), 205(10), 57 (84), 41 (17).

Synthesis ofdimethylsilyl{(2-methyl-4-(3′,5′-di-tert-butylphenyl)-1-indenyl)-7-(2,5-dimethyl-cyclopental[1,2-b:4,3-b′]-dithiophene)}zirconiumdichloride [C-2]

A 2.3 M HexLi solution (4.61 mL, 10.60 mmol) was added dropwise at 0° C.to a solution of 3.00 g of1-[2-methyl-4-(3′,5′-di-tert-butylphenyl)indenyl]-7-(2,5-dimethyl-cyclopenta[1,2-b:4,3-b′]-dithiophene)dimethylsilane(Mw=580.96, 5.16 mmol, HexLi:ligand=2.05:1) in 30 mL of Et₂O. At the endof the addition, the resulting brown solution was stirred for 2 h atroom temperature with final formation of a light brown suspension.Subsequently a suspension of 1.20 g of ZrCl₄ (Mw=233.03, 5.15 mmol,ZrCl₄:ligand=1:1) in 20 mL of toluene was added at 0° C. The reactionmixture was then allowed to warm up to room temperature and stirred for16 h. The solvents were removed in vacuo and the crude residue wasextracted with 75 mL of toluene. The extract was treated with 55 mL of amixture of isobutanol/toluene ca. 1/10 (v/v), stirred for 15 min at roomtemperature and then filtered. The filtrate was eliminated, while theinsoluble in isobutanol/toluene was dried to give 2.20 g of an orangepowder, which resulted to be by ¹H-NMR analysis the desired complex freefrom LiCl (isolated yield=57.6%).

¹H NMR (δ, ppm, CD₂Cl₂): 1.21 (s, 3H, Si—CH₃); 1.36 (s, 18H, t-Bu); 1.38(s, 3H, Si—Ch₃); 2.38 (s, 3H, CH₃); 2.46 (d, 3H, J=1.17 Hz, CH₃); 2.64(d, 3H, J=1.17 Hz, CH₃); 6.71 (q, 1H, J=1.17 Hz, CH); 6.86 (q, 1H,J=1.17 Hz, CH); 6.87 (bs, 1H, Cp-H); 6.93-7.73 (m, 6H, Ar).

Example 3 Synthesis ofdimethylsilyl{(2-ethyl-4-(4′-tert-butylphenyl)-1-indenyl)-7-(2,5-dimethyl-cyclopental[1,2-b:4,3-b′]-dithiophene)}zirconiumdichloride [C-3] Synthesis ofchloro(2-ethyl-4′-tert-butylphenyl-1-indenyl)dimethylsilane

A 2.3 M HexLi (hexylithium) solution in hexane (8.30 mL, 19.09 mmol,HexLi:2-Et-4-(4′-t-BuPh)-1-Ind=1.06:1) was added dropwise at 0° C. to asolution of 5.0 g of 2-ethyl-4-(4′-tert-butylphenyl)-1-indene(MW=276.42, 18.09 mmol) in 50 mL of Et₂O. At the end of the addition,the resulting orange solution was allowed to warm up to room temperatureand stirred for 1 h. An aliquot of this solution was quenched with CD₃ODand dried: the related ¹H NMR analysis in CD₂Cl₂ showed completeconversion of the starting indene to the corresponding lithium salt. Asolution of Me₂SiCl₂ (99%, 2.20 mL, d=1.064, MW=129.06, 17.96 mmol,Me₂SiCl₂/2-Et-4-(4′-t-BuPh)IndLi=1:1) in 10 mL of Et₂O was added at 0°C. to the lithium salt solution, previously cooled to 0° C. too. Thereaction mixture was allowed to warm up to room temperature and stirredfor 1 h and 30 min with final formation of a light yellow suspension.The solvents were removed in vacuo and the residue extracted with 50 mLof toluene to remove the LiCl. The filtrate was brought to dryness invacuo at 40° C. to give a sticky orange solid as product (6.60 g).Yield=99.6%.

¹NMR (δ, ppm, CD₂Cl₂): 0.27 (s, 3H, Si—CH₃); 0.48 (s, 3H, Si—CH₃); 1.29(t, 3H, J=7.58 Hz, CH₃); 1.45 (s, 9H, t-Bu); 2.54-2.88 (m, 2H, CH₂);3.83 (s, 1H, CH); 6.92 (s, 1H, Cp-H); 7.20-7.59 (m, 7H, Ar). m/z (%):370 (22) [M⁺+2], 369 (18) [M⁺+1], 368 (55) [M⁺], 355 (11), 353 (27), 275(17), 274 (23), 219 (14), 217 (14), 215 (17), 202 (18), 95 (36), 93(100), 57 (47), 41 (14).

Synthesis of1-(2-ethyl-4-(4′-tert-butylphenylindenyl)-7-(2,5-dimethyl-cyclopenta[1,2-b:4,3-b′]-dithiophene)dimethylsilane

A 2.3 M HexLi solution in hexane (4.40 mL, 10.12 mmol) was addeddropwise at 0° C. to a suspension of 2.07 g of2,5-dimethyl-7H-cyclopenta[1,2-b:4,3-b′]-dithiophene (Mw=206.32, 10.03mmol, HexLi: MeTh₂Cp=1.01:1) in 30 mL of Et₂O. The resulting brownsolution was stirred at 0° C. for 1 h and then a solution of 3.71 g ofchloro[2-ethyl-4-(4′-tert-butylphenyl)-1-indenyl]dimethylsilane(Mw=369.02, 10.05 mmol, 2-Et-4-(4′-t-BuPh)IndSiMe₂Cl:MeTh₂Cp=1:1) in 25mL of Et₂O was added at the same temperature. The reaction mixture wasthen allowed to warm up to room temperature and stirred for 16 h withfinal formation of a green-brown suspension. The solvents wereevaporated under reduced pressure and the residue was extracted with 40mL of toluene. The extract was dried in vacuo to give 5.70 g of a brownsticky solid, which resulted to be the desired product by ¹H-NMRspectroscopy (purity by ¹H-NMR=91.3 wt %, isolated yield=96.3%). About8.7 wt % of starting2,5-dimethyl-7H-cyclopenta[1,2-b:4,3-b′]-dithiophene was also present.

¹H NMR (δ, ppm, CD₂Cl₂): −0.29 (s, 3H, Si—CH₃); −0.30 (s, 3H, Si—CH₃);1.26 (t, 3H, J=7.58 Hz, CH₃); 1.44 (s, 9H, t-Bu); 2.44-2.75 (m, 2H,CH₂); 2.59 (bs, 3H, CH₃); 2.61 (bs, 3H, CH₃); 4.07 (bs, 2H, CH); 6.90(s, 1H, Cp-H); 6.92 (q, 1H, J=1.17 Hz, CH); 6.94 (q, 1H, J=1.17 Hz, CH);7.06-7.56 (m, 7H, Ar).

Synthesis ofdimethylsilyl{(2-ethyl-4-(4′-tert-butylphenyl)-1-indenyl)-7-(2,5-dimethyl-cyclopenta[1,2-b:4,3-b′]-dithiophene)}zirconiumdichloride [C-3]

A 2.3 M HexLi solution (4.61 mL, 10.60 mmol) was added dropwise at 0° C.to a solution of 2.86 g of1-[2-ethyl-4-(4′-tert-butylphenyl)indenyl]-7-(2,5-dimethyl-cyclopenta[1,2-b:4,3-b′]-dithiophene)dimethylsilane(Mw=538.88, 5.31 mmol, HexLi:ligand=2:1) in 30 mL of Et₂O. The resultingbrown solution was allowed to warm up to room temperature and stirredfor 2 h. Then a suspension of 1.24 g of ZrCl₄ (Mw=233.03, 5.32 mmol,ZrCl₄:ligand=1:1) in 30 mL of toluene was added. The reaction mixturewas stirred at room temperature for 1 h and then the solvents wereremoved in vacuo. The residue was treated with 50 mL of a mixture ofisobutanol/toluene ca. 1/3 (v/v), stirred for 10 min at room temperatureand then filtered. The filtrate was eliminated, while the insoluble inisobutanol/toluene was dried to give 1.75 g of an orange powder, whichresulted to be by ¹H-NMR analysis the desired catalyst free from LiCl(isolated yield=46.9%).

¹H NMR (δ, ppm, CD₂Cl₂): 0.11 (s, 6H, Si—CH₃); 1.17 (t, 3H, J=7.34 Hz,CH₃); 1.38 (s, 9H, t-Bu); 2.46 (d, 3H, J=1.17 Hz, CH₃); 2.62 (d, 3H,J=1.17 Hz, CH₃); 2.53-2.94 (m, 2H, CH₂); 6.68 (q, 1H, J=1.17 Hz, CH);6.82 (q, 1H, J=1.17 Hz, CH); 6.92-7.74 (m, 8H, Cp-H and Ar).

Comparative Example 4 Synthesis ofdimethylsilyl{(2-methyl-4-phenyl-1-indenyl)-7-(2,5-dimethyl-cyclopenta[1,2-b:4,3-b′]-dithiophene)}zirconiumdichloride [C-4] Synthesis ofchloro(2-methyl-4-phenyl-1-indenyl)dimethylsilane

A 2.5 M solution of n-BuLi in hexane (4.85 mL, 12.12 mmol) was added at0° C. to a solution of 2.50 g of 2-methyl-4-phenyl-indene (BoulderScientific Company, Mw=206.29, 12.12 mmol, n-BuLi:2-Me-4-Ph-Ind=1:1) in30 mL of ether. The resulting mixture was stirred for additional 2 h atroom temperature with final formation of an orange solution. Thissolution was cooled again to 0° C. and added slowly of a solution of1.58 mL of dichlorodimethylsilane (Aldrich, Mw=129.06, d=1.064, 13.03mmol, Me₂SiCl₂:2-Me-4-Ph-Ind=1.08:1) in 20 mL of ether. The reactionmixture was then allowed to warm up to room temperature and stirred for1 h. The final straw yellow suspension was concentrated under vacuum andthe residue was extracted with 50 mL of toluene. The extract was driedunder vacuum to give 3.36 g of a straw yellow solid, which wascharacterized by GC-MS analysis and ¹H-NMR spectroscopy. Yield=92.8%.

¹H NMR (δ, ppm, CDCl₃): 0.24 (s, 3H, Si—CH₃); 0.48 (s, 3H, Si—CH₃); 2.31(d, 3H, CH₃, J=0.78 Hz); 3.70 (bs, 1H, CH); 6.85 (m, 1H, CH, J=0.78 Hz);7.19-7.59 (m, 8H, Ar). m/z (%): 300 (26) [M⁺+2], 299 (18) [M⁺+1], 298(72) [M⁺], 205 (23), 204 (45), 203 (28), 202 (32), 189 (15), 165 (13),95 (35), 93 (100).

Synthesis of(2-methyl-4-phenyl-1-indenyl)-7-(2,5-dimethyl-cyclopenta[1,2-b:4,3-b′]-dithiophene)dimethylsilane

A 2.5 M solution of n-BuLi in hexane (2.72 mL, 6.80 mmol) was added at−20° C. to a solution of 1.40 g of2,5-dimethyl-7H-cyclopenta[1,2-b:4,3-b′]-dithiophene (Mw=206.32, 90.7%,6.15 mmol, n-BuLi:MeTh₂Cp=1.1:1) in 30 mL of ether. The resultingmixture was stirred for additional 1 h at 0° C. with final formation ofa dark brown suspension. This suspension was cooled again to −20° C. andadded slowly of a solution of 1.90 g ofchloro(2-methyl-4-phenyl-1-indenyl)dimethylsilane (Mw=298.89, 6.37 mmol,(2-Me-4-Ph-1-Ind)SiMe₂Cl:MeTh₂Cp=1.04:1) in 20 mL of ether. The reactionmixture was then allowed to warm up to room temperature and stirred for2 h. The final dark solution (almost black) was concentrated undervacuum and the residue extracted with 50 mL of toluene to give an oilyproduct, which was treated at 30° C. under stirring with 30 mL ofpentane. After 15 min stirring a powdery solid was formed and isolatedby filtration. After drying in vacuo, 2.03 g of a brown product wasrecovered.

Purity (by GC-MS)=83.8%. Yield of the pure product=59.0%. ¹H NMR (δ,ppm, CDCl₃): −0.35 (s, 3H, Si—CH₃); −0.32 (s, 3H, Si—CH₃); 2.23 (d, 3H,CH₃, J=0.78 Hz); 2.55 (bs, 3H, CH₃); 2.58 (bs, 3H, CH₃); 3.96 (s, 1H,CH); 4.04 (s, 1H, CH); 6.82 (q, 1H, CH, J=0.78 Hz); 6.86 (q, 1H, CH,J=1.17 Hz); 6.88 (q, 1H, CH, J=1.17 Hz); 7.13-7.59 (m, 8H, Ar). m/z (%):469 (10) [M⁺+1], 468 (24) [M⁺], 264 (28), 263 (100), 248 (14), 247 (21),235 (20), 205 (13), 203 (16), 190 (10), 59 (14).

Synthesis ofdimethylsilyl{(2-methyl-4-phenyl-1-indenyl)-7-(2,5-dimethyl-cyclopenta[1,2-b:4,3-b′]-dithiophene)}zirconiumdichloride [C-4]

A solution of 2.58 g (5.5 mmol) of(2-methyl-4-phenyl-1-indenyl)-7-(2,5-dimethyl-cyclopenta[1,2-b:4,3-b′]-dithiophene)dimethylsilanein 40 mL of ether was treated at −70° C. with 7.0 mL of a 1.6 M n-BuLisolution (11.2 mmol). The reaction mixture was allowed to reach roomtemperature and stirred for 1 h. The solvent was removed under reducedpressure and the dilithium salt obtained was suspended in hexane. Aftercooling to −70° C., 1.28 g (5.5 mmol) of ZrCl₄ were added. The reactionmixture was stirred at room temperature overnight, the yellowprecipitate was filtered, washed twice with ether, dried and finallyrecrystallized from CH₂Cl₂. Yield 1.65 g (48%). The title compound wascharacterized by ¹H NMR spectroscopy.

Example 5 Synthesis ofdimethylsilanediyl{(1-(2-methyl-4-naphthylindenyl)-7-(2,5dimethyl-cyclopenta[1,2-b:4,3-b′]-dithiophene)}zirconiumdichloride [C-5] Synthesis ofchloro(2-methyl-4-naphthyl-1-indenyl)dimethylsilane

A 1.5 M MeLi solution in Et₂O (9.90 mL, 14.85 mmol,MeLi:2-Me-4-naphthyl-1-indene=1:1) was added dropwise at 0° C. to asolution of 3.88 g of 2-methyl-4-naphthylindene (MW=256.35, 98%, 14.83mmol) in 45 mL of Et₂O. At the end of the addition a light yellowsuspension was obtained. The latter was kept at 0° C. for 15 min andthen allowed to warm up to room temperature. After 1 h stirring analiquot of the suspension was taken, treated with D₂O and dried: its ¹HNMR analysis in CD₂Cl₂ showed complete conversion of2-methyl-4-naphthylindene to a 70:30 mixture of1-deuterium-2-methyl-4-naphthyl-1-indene and1-deuterium-2-methyl-7-naphthyl-1-indene (see below ¹H NMR analysis).The expected lithium salt was quantitatively obtained. It was then addedat 0° C. to a solution of Me₂SiCl₂ (98%, 1.96 g, d=1.064, MW=129.06,14.88 mmol, Me₂SiCl₂/2-Me-4-naphthyl-1-IndLi=1:1) in 30 mL of Et₂O,previously cooled to 0° C. too. The reaction mixture was allowed to warmup to room temperature and stirred for 20 h with final formation of awhite suspension. After this time a ¹H NMR analysis showed completeconversion of the starting material. The solvents were removed in vacuoand the residue was extracted with 50 mL of toluene to remove the LiCl.The light yellow filtrate was brought to dryness in vacuo at 40° C. togive a light yellow solid as product, which was analysed by NMRspectroscopy (5.28 g). The latter showed the presence of the desiredproduct as a mixture of two diastereoisomers in ratio of 1 (1):1.4 (2),probably due to a blocked rotation around the C4-naphthyl bond. Crudeyield=100%. The product was used as such in the next step withoutfurther purification.

¹H NMR (δ, ppm, CD₂Cl₂): 0.28 (s, 3H, Si—CH₃, 1); 0.35 (s, 3H, Si—CH₃,2); 0.48 (s, 3H, Si—CH₃, 1); 0.53 (s, 3H, Si—CH₃, 2); 2.20 (m, 3H,J=0.78 Hz, CH₃, 2); 2.22 (m, 3H, J=0.78 Hz, CH₃, 1); 3.76 (s, 1H, CH,2); 3.77 (s, 1H, CH, 1); 6.18 (m, 1H, Cp-H, 2); 6.28 (m, 1H, Cp-H, 1);7.26-7.98 (m, 20H, Ar, 1 and 2). NOESY (CD₂Cl₂) δ¹H/δ¹H=0.28, 0.48/3.77(Si—CH₃/CH, 1); 0.35, 0.53/3.76 (Si—CH₃/CH, 2); 2.22/3.77 (CH₃/CH, 1);2.20/3.76 (CH₃/CH, 2); 2.22/6.28 (CH₃/Cp-H, 1); 2.20/6.18 (CH₃/Cp-H, 2);6.28/7.59-7.80 (Cp-H/H7, 1); 6.18/7.59-7.80 (Cp-H/H7, 2). COSY (CD₂Cl₂)δ¹/δ¹H/=2.22/3.77 (CH₃/CH, 1); 2.20/3.76 (CH₃/CH, 2); 2.22/6.28(CH₃/Cp-H, 1); 2.20/6.18 (CH₃/Cp-H, 2).

Synthesis of1-(2-methyl-4-naphthylindenyl)-7-(2,5-dimethyl-cyclopenta[1,2-b:4,3-b′]-dithiophene)dimethylsilane

A 2.5 M solution of n-BuLi in hexane (5.40 mL, 13.50 mmol) was addeddropwise at 0° C. under stirring to a suspension of 2.81 g of2,5-dimethyl-7H-cyclopenta[1,2-b:4,3-b′]-dithiophene (99%, Mw=206.32,13.48 mmol, n-BuLi: MeTh₂Cp=1.00: 1) in 40 mL of Et₂O in a 100 mLSchlenk flask. The resulting dark brown suspension was stirred at 0° C.for 1 h, then cooled to −20° C. and added slowly to a solution of 4.71 gof chloro(2-methyl-4-naphthyl-1-indenyl)dimethylsilane (Mw=348.95, 13.50mmol, 2-Me-4-naphthyl-IndSiMe₂Cl:MeTh₂Cp=1:1) in 30 mL of Et₂O,previously cooled to −20° C. too. The reaction mixture was kept for 15min at −20° C. and then allowed to warm up to room temperature andstirred for 2 h. CH₃OH (1 mL) was added and the suspension turned frombrown to yellow. The solvents were removed in vacuo and the residue wasextracted with 50 mL of toluene to give 6.64 g of a pitch-brown solid.Since its ¹H NMR analysis in CD₂Cl₂ showed the presence of unwelcomeby-products, the solid was washed first with pentane and then with Et₂Oyielding after drying 2.01 g of a white powder, which was analysed byNMR spectroscopy and GC-MS analysis. The product resulted a mixture oftwo diastereoisomers in ratio of ca. 1 (1):1.4 (2), probably due to ablocked rotation around the C4-naphthyl bond. Isolated yield 28.7%.Purity 97.3% by GC-MS. Bis(2-methyl-4-naphthyl-1-indenyl)dimethylsilanewas present in 1.1% wt. by GC-MS.

¹H NMR (δ, ppm, CD₂Cl₂): −0.25 (s, 3H, Si—CH₃, 1); −0.22 (s, 3H, Si—CH₃,2); −0.21 (s, 3H, Si—CH₃, 1); −0.16 (s, 3H, Si—CH₃, 2); 2.21 (d, 3H,J=0.98 Hz, CH₃, 2); 2.23 (D, 3H, J=0.98 Hz, CH₃, 1); 2.64 (m, 6H, CH₃, 1and 2); 2.66 (m, 6H, CH₃, 2 and 1); 4.10 (S, 2H, CH, H1, 1 and 2); 4.16(s, 1H, CH, 1); 4.22 (s, 1H, CH, 2); 6.26 (m, 1H, Cp-H, 2); 6.36 (m, 1H,Cp-H, 1); 6.97-7.01 (m, 4H, CH, 1 and 2); 7.27-8.03 (m, 20H, Ar, 1 and2). NOESY (CD₂Cl₂) δ¹H/δ¹H=−0.25/2.23 (Si—CH₃/CH₃, 1); −0.22/2.21(Si—CH₃/CH₃, 2); −0.25, −0.22, −0.21, −0.16/4.10 (Si—CH₃/CH, H1, 1 and2); −0.25, −0.21/4.16 (Si—CH₃/CH, 1); −0.22, −0.16/4.22 (Si—CH₃/CH, 2);2.21, 2.23/4.10 (CH₃/CH, H1, 1 and 2); 2.23/4.16 (CH₃/CH, 1); 2.21/4.22(CH₃/CH, 2); 2.64, 2.66/6.97-7.01 (CH₃/CH, 1 and 2). COSY (CD₂Cl₂)δ¹H/δ¹H=2.21, 2.23/4.10 (CH₃/CH, H1, 1 and 2); 2.23/6.36 (CH₃/Cp-H, 1);2.21/6.26 (CH₃/Cp-H, 2); 2.64, 2.66/4.16 (CH₃/CH, 1); 2.64, 2.66/4.22(CH₃/CH, 2); 4.10/6.26, 6.36 (CH, H1/Cp-H, 1 and 2); 4.16/6.97-7.01(CH/CH, 1); 4.22/6.97-7.01 (CH/CH, 2). ¹³C NMR (δ, ppm, CD₂Cl₂): −8.04(Si—CH₃, 1C, 2); −7.92 (Si—CH₃, 1C, 1); −7.54 (Si—CH₃, 1C, 2); −7.46(Si—CH₃, 1C, 1); 16.26 (CH₃ in MeTh₂Cp, 4C, 1 and 2); 17.92 (CH₃ in 2,2C, 1 and 2); 39.77 (CH in MeTh₂Cp, 1C, 1); 39.87 (CH in MeTh₂Cp, 1C,2); 47.43 (CH, 1C, 1); 47.46 (CH, 1C, 2); 116.82 (CH in MeTh₂Cp, 2C, 1);116.91 (CH in MeTh₂Cp, 2C, 2); 126.82 (Cp-H, 1C, 1); 126.91 (Cp-H, 1C,2); 122.63-128.56 (Ar, 20 CH, 1 and 2); 132.39-147.86 (Ar, 20 C, 1 and2). The peaks were assigned by a DEPT experiment. m/z (%): 519 (19)[M⁺+1], 518 (43) [M⁺], 314 (29), 313 (100), 297 (14), 264 (18), 263(88), 235 (16), 204 (13), 203 (15).

Synthesis ofdimethylsilanediyl{(1-(2-methyl-4-naphthylindenyl)-7-(2,5-dimethyl-cyclopenta[1,2-b:4,3-b′]-dithiophene)}zirconiumdichloride [C-5]

A 2.5 M solution of n-BuLi in hexane (3.40 mL, 8.50 mmol) was addeddropwise at 0° C. under stirring to a yellow-brown suspension of 2.16 gof 1-(2-methyl-4-naphthylindenyl)-7-(2,5 -dimethyl-cyclopenta[1,2-b:4,3-b′]-dithiophene)dimethylsilane (Mw=518.81, 4.16 mmol,n-BuLi:ligand=2.04:1) in 40 mL of Et₂O. The resulting brown solution wasallowed to warm up slowly to room temperature and stirred for 1 h. Thenit was cooled to 0° C. to add slowly a suspension of 0.97 g of ZrCl₄(Mw=233.03, 4.16 mmol, ZrCl₄:ligand=1:1) in 20 mL of toluene, previouslycooled to 0° C. too. The reaction mixture was stirred at roomtemperature for 2 h with final formation of a dark orange-redsuspension. The solvents were removed in vacuo and the obtainedred-brown solid was treated at room temperature with 30 mL of a 1/5(v/v) isobutanol/toluene mixture. After 15 min stirring the suspensionwas filtered on a G3 frit: the filtrate was discarded, while the residuewas dried at room temperature in vacuo for 8 h to give an orange powderas product (1.41 g, free from LiCl). Isolated yield 49.9%.

¹H NMR (δ, ppm, CDCl₃): 1.22 (s, 3H, Si—CH₃); 1.42 (s, 3H, Si—CH₃); 2.32(s, 3H, CH₃ in 2); 2.51 (s, 3H, CH₃ in Me₂ThCp); 2.61 (s, 3H, CH₃ inMe₂ThCp); 6.45 (s, 1H, Cp-H); 6.70 (s, 1H, CH); 6.79 (s, 1H, CH);7.00-7.95 (m, 10H, Ar).

Polymerization Examples 6-12 and Comparative Examples 13-14

The cocatalyst methylalumoxane (MAO) was a commercial product which wasused as received (Witco AG, 10% wt/vol toluene solution, 1.7 M in Al).The catalyst mixture was prepared by dissolving the desired amount ofthe metallocene with the proper amount of the MAO solution, (Al/Zrratio=500) obtaining a solution which was stirred for 10 min at ambienttemperature before being injected into the autoclave.

Polymerization (General Procedure)

2 mmol of Al(i-Bu)₃ (as a 1M solution in hexane) and 600 g of propylenewere charged at room temperature in a 2.5-L jacketed stainless-steelautoclave, equipped with magnetically driven stirrer and a 35-mLstainless-steel vial, connected to a thermostat for temperature control,previously purified by washing with an Al(i-Bu)₃ solution in hexanes anddried at 50° C. in a stream of propene. The autoclave was thenthermostatted at the polymerization temperature (Tp), and then thetoluene solution containing the catalyst/cocatalyst mixture was injectedin the autoclave by means of nitrogen pressure through thestainless-steel vial, and the polymerization carried out at constanttemperature for 1 hour. The polymerization was stopped by pressurizingCO into the reactor. After venting the unreacted monomer and cooling thereactor to room temperature, the polymer was dried under reducedpressure at 60° C.

The polymerization conditions and the characterization data of theobtained polymers are reported in Table 1

TABLE 1 Metallocene Activity I.V. Tm Ex. Type mg Tp ° C. (kg/(g_(cat) ×h)) (dL/g) (° C.) mm %  6 C-1 0.5 60 140 1.5 147 94.6  7 C-1 0.5 70 2401.1 145 94.2  8 C-2 0.5 60 60 1.9 150 n.a.  9 C-2 0.5 70 80 1.4 145 n.a.10 C-3  0.5. 60 120 1.5 150 n.a. 11 C-3 0.5 70 224 1.1 147 n.a. 12 C-50.5 70 60 1.2 156 n.a.  13* C-4 1   60 100 1.3 146 94.1  14* C-4 0.5 70126 1.0 143 93.9 *comparative n.a. = not available

1. A metallocene compound of formula (I):

wherein: M is selected from the group consisting of zirconium, titaniumand hafnium; X, same or different, is a hydrogen atom, a halogen atom, aR, OR, OR′O, OSO₂CF₃, OCOR, SR, NR₂ or PR₂ group, wherein the Rsubstituents are linear or branched, saturated or unsaturatedC₁-C₂₀-alkyl, C₃-C₂₀-cycloalkyl, C₆-C₂₀-aryl, C₇-C₂₀-alkylaryl,C₇-C₂₀-arylalkyl radicals, optionally containing one or more heteroatomsbelonging to groups 13-17 of the Periodic Table of the Elements and theR′ substituent is a divalent radical selected from the group consistingof C₁-C₂₀-alkylidene, C₆-C₂₀-arylidene, C₇-C₂₀-alkylarylidene, andC₇-C₂₀-arylalkylidene; R¹ is a linear C₁-C₂₀-alkyl radical; R² is ahydrogen atom or a linear or branched, saturated or unsaturatedC₁-C₂₀-alkyl radical; R³ and R⁴, same or different, are hydrogen atomsor a linear or branched, saturated or unsaturated C₁-C₂₀-alkyl,C₃-C₂₀-cycloalkyl, C₆-C₂₀-aryl, C₇-C₂₀-alkylaryl, C₇-C₂₀-arylalkylradicals, optionally containing one or more heteroatoms belonging togroups 13-17 of the Periodic Table of the Elements; or they can formtogether a condensed saturated or unsaturated 5 or 6 membered ring,optionally containing one or more heteroatoms belonging to groups 13-16of the Periodic Table of the Elements, said ring optionally bearing oneor more substituents; R⁵ and R⁶, same or different, are hydrogen atomsor a linear or branched, saturated or unsaturated C₁-C₂₀-alkyl,C₃-C₂₀-cycloalkyl, C₆-C₂₀-aryl, C₇-C₂₀-alkylaryl, C₇-C₂₀-arylalkylradicals, optionally containing one or more heteroatoms belonging togroups 13-17 of the Periodic Table of the Elements; R⁷ and R⁸, same ordifferent, are hydrogen atoms or a linear or branched, saturated orunsaturated C₁-C₂₀-alkyl, C₃-C₂₀-cycloalkyl, C₆-C₂₀-aryl,C₇-C₂₀-alkylaryl, C₇-C₂₀-arylalkyl radicals, optionally containing oneor more heteroatoms belonging to groups 13-17 of the Periodic Table ofthe Elements; A, same or different, is a sulphur (S) atom or an oxygen(O) atom; Q is a radical of formula (II), (III) or (IV)) being bonded tothe indenyl at the position marked with the symbol *;

 wherein: T¹ is a sulphur (S) atom, an oxygen (O) atom or a NR group, Rbeing defined as above; R⁹, R¹⁰ and R¹¹, same or different, are hydrogenatoms or a linear or branched, saturated or unsaturated C₁-C₂₀-alkyl,C₃-C₂₀-cycloalkyl, C₆-C₂₀-aryl, C₇-C₂₀-alkylaryl, C₇-C₂₀-arylalkylradicals, optionally containing one or more heteroatoms belonging togroups 13-17 of the Periodic Table of the Elements; or R⁹ and R¹⁰ canform together a condensed saturated or unsaturated 5 or 6 membered ring,optionally containing one or more heteroatoms belonging to groups 13-16of the Periodic Table of the Elements, said ring optionally bearing oneor more substituents; T², T³, T⁴, T⁵ and T⁶, same or different, arecarbon atoms (C) or nitrogen atoms (N); each of m¹, m², m³, m⁴ and m⁵ is0 when the correspondent T², T³, T⁴, T⁵ and T⁶ is a nitrogen atom and is1 when the correspondent T², T³, T⁴, T⁵ and T⁶ is a carbon atom; R¹²,R¹³, R¹⁴, R¹⁵ and R¹⁶ same or different, are hydrogen atoms or a linearor branched, saturated or unsaturated C₁-C₂₀-alkyl, C₃-C₂₀-cycloalkyl,C₆-C₂₀-aryl, C₇-C₂₀-alkylaryl, C₇-C₂₀-arylalkyl radicals, optionallycontaining one or more heteroatoms belonging to groups 13-17 of thePeriodic Table of the Elements; or two vicinal R¹², R¹³, R¹⁴, R¹⁵ canform together a condensed saturated or unsaturated 5 or 6 membered ring,optionally containing one or more heteroatoms belonging to groups 13-16of the Periodic Table of the Elements, said ring optionally bearing oneor more substituents; with the provisos that at least one of R¹², R¹³,R¹⁴, R¹⁵ and R¹⁶ is different from hydrogen atoms, and that no more thantwo of T², T³, T⁴, T⁵ and T⁶ are nitrogen atoms.
 2. The metallocenecompound according to claim 1 wherein M is zirconium or hafnium; X is ahalogen atom, a R, OR′O or OR group; and R⁵ and R⁶ are a C₁-C₂₀-alkylradical; R⁷ and R⁸ are C₁-C₂₀-alkyl or C₆-C₂₀-aryl radicals.
 3. Themetallocene compound according to claim 1 wherein in the radicals offormula (II) and (III), T¹ is oxygen or sulphur; R⁹ and R¹⁰ are a linearor branched, saturated or unsaturated C₁-C₂₀-alkyl radical or they forma condensed saturated or unsaturated 5 or 6 membered ring, optionallycontaining one or more heteroatoms belonging to groups 13-16 of thePeriodic Table of the Elements, said ring optionally bearing one or moresubstituents; and R¹¹ is a hydrogen atom.
 4. The metallocene compoundaccording to claim 1 wherein Q is a radical of formula (IVa) bonded tothe indenyl at the position indicated by the symbol *:

wherein: R¹⁴ is different from a hydrogen atom.
 5. The metallocenecompound according to claim 4 wherein R¹⁴ is a branched, saturated orunsaturated C₁-C₂₀-alkyl or C₆-C₂₀-aryl radical.
 6. The metallocenecompound according to claim 1 wherein Q is a radical of formula (IVb)bonded to the indenyl at the position indicated by the symbol *:

wherein: R¹³ and R¹⁵ are different from hydrogen atoms; and R¹⁴ is ahydrogen atom or a R¹⁸ or OR¹⁸ group, wherein R¹⁸ is a linear orbranched, saturated or unsaturated C₁-C₂₀-alkyl or C₆-C₂₀-aryl radicaloptionally containing one or more heteroatoms belonging to groups 13-17of the Periodic Table of the Elements.
 7. The metallocene compoundaccording to claim 6 wherein R¹³ and R¹⁵ are a branched, saturated orunsaturated C₁-C₂₀-alkyl or a CF₃ radical; and R¹⁴ is a hydrogen atom ora OR¹⁸ group, wherein R¹⁸ is a linear or branched, saturated orunsaturated C₁-C₂₀-alkyl or C₆-C₂₀-aryl radical.
 8. The metallocenecompound according to claim 1 wherein Q is a radical of formula (IVc)bonded to the indenyl at the position indicated by the symbol *:

wherein: R¹² and R¹⁵ are different from hydrogen atoms.
 9. Themetallocene compound according to claim 8 wherein R¹² and R¹⁵ are alinear, saturated or unsaturated C₁-C₂₀-alkyl radical.
 10. Themetallocene compound according to claim 1 wherein Q is a radical offormula (IVd) bonded to the indenyl at the position indicated by thesymbol *:

wherein R¹² and R¹⁶ are different from hydrogen atoms.
 11. Themetallocene compound according to claim 10 wherein R¹² and R¹⁶ are alinear, saturated or unsaturated C₁-C₂₀-alkyl radicals.
 12. Themetallocene compound according to claim 1 wherein Q is a radical offormula (IVe) bonded to the indenyl at the position indicated by thesymbol *:

wherein R¹² and R¹³ are different from hydrogen atoms.
 13. Themetallocene compound according to claim 12 wherein R¹² and R¹³ arelinear, saturated or unsaturated C₁-C₂₀-alkyl radical, or they form asaturated or unsaturated condensed 5 or 6 membered ring optionallycontaining one or more heteroatoms belonging to groups 13-16 of thePeriodic Table of the Elements, said ring optionally bearing one or moresubstituents.
 14. The metallocene compound according to claim 12 whereinR¹² and R¹³ form a saturated or unsaturated condensed 5 or 6 memberedring optionally containing one or more heteroatoms belonging to groups13-16 of the Periodic Table of the Elements, said ring optionallybearing one or more substituents.
 15. The metallocene compound accordingto claim 1 wherein Q is a radical of formula (IVf) being bonded to theindenyl at the position indicated by the symbol *:

wherein at least one among R¹³, R¹⁴, R¹⁵ and R¹⁶ is different from ahydrogen atom.
 16. The metallocene compound according to claim 15wherein R¹⁵ and R¹⁶ are hydrogen atoms; and R¹³ and R¹⁴ are a linear orbranched, saturated or unsaturated C₁-C₂₀-alkyl radicals, or they form asaturated or unsaturated condensed 5 or 6 membered ring optionallycontaining one or more heteroatoms belonging to groups 13-16 of thePeriodic Table of the Elements, said ring optionally bearing one or moresubstituents.
 17. The metallocene compound according to claim 1 havingformula (Ia) or (Ib):

wherein; R² is a linear or branched, saturated or unsaturatedC₁-C₂₀-alkyl radical; and R³ and R⁴ form together a condensed saturated5 or 6 membered aliphatic ring.
 18. A compound of formula (V)

and its double bond isomer; wherein R¹ is a linear C₁-C₂₀-alkyl radical;R² is a hydrogen atom or a linear or branched, saturated or unsaturatedC₁-C₂₀-alkyl radical; R³ and R⁴, same or different, are hydrogen atomsor a linear or branched, saturated or unsaturated C₁-C₂₀,C₃-C₂₀-cycloalkyl, C₆-C₂₀-arly, C₇-C₂₀-arylalky, C₇-C₂₀-arylalkylradicals, optionally containing one or more heteroatoms belonging togroups 13-17 of the Periodic Table of the Elements; or they can formtogether a condensed saturated or unsaturated 5 or 6 membered ring,optionally containing one or more heteroatoms belonging to groups 13-16of the Periodic Table of the Elements, said ring optionally bearing oneor more substituents; R⁵ and R⁶, same or different, are hydrogen atomsor a linear or branched, saturated or unsaturated C₁-C₂₀-alkyl,C₃-C₂₀-cycloalkyl, C₆-C₂₀-aryl, C₇-C₂₀-alkylaryl, C₇-C₂₀-arylalkylradicals, optionally containing one or more heteroatoms belonging togroups 13-17 of the Periodic Table of the Elements; R⁷ and R⁸, same ordifferent, are hydrogen atoms or a linear or branched, saturated orunsaturated C₁-C₂₀-alkyl, C₃-C₂₀-cycloalkyl, C₆-C₂₀-aryl,C₇-C₂₀-alkylaryl, C₇-C₂₀-arylalkyl radicals, optionally containing oneor more heteroatoms belonging to groups 13-17 of the Periodic Table ofthe Elements; A, same or different, is a sulphur (S) atom or an oxygen(O) atom; Q is a radical of formula (II), (III) or (IV)) being bonded tothe indenyl at the position marked with the symbol *;

 wherein: T¹ is a sulphur (S) atom, an oxygen (O) atom or a NR group Rbeing defined as above; R⁹, R¹⁰ and R¹¹, same or different, are hydrogenatoms Or a linear or branched, saturated or unsaturated C₁-C₂₀-alkyl,C₃-C₂₀-cycloalkyl, C₆-C₂₀-aryl, C₇-C₂₀-arylalkyl, C₇-C₂₀-arylalkylradicals, optionally containing one or more heteroatoms belonging togroups 13-17 of the Periodic Table of the Elements; or R⁹ and R¹⁰ canform together a condensed saturated or unsaturated 5 or 6 membered ring,optionally containing one or more heteroatoms belonging to groups 13-16of the Periodic Table of the Elements, said ring optionally bearing oneor more substituents; T², T³, T⁴, T⁵ and T⁶, same or different, arecarbon atoms (C) or nitrogen atoms (N); each of m¹, m², m³, m⁴ and m⁵ is0 when the correspondent T², T³, T⁴, T⁵ and T⁶ is a nitrogen atom and is1 when the correspondent T², T³, T⁴, T⁵ and T⁶ is a carbon atom; R¹²,R¹³, R¹⁴, R¹⁵ and R⁶, same or different, are hydrogen atoms or a linearor branched, saturated or unsaturated C₁-C₂₀-alkyl, C₃-C₂₀-cycloalkyl,C₆-C₂₀-aryl, C₇-C₂₀-alkylaryl, C₇-C₂₀-arylalkyl radicals, optionallycontaining one or more heteroatoms belonging to groups 13-17 of thePeriodic Table of the Elements; or two vicinal R¹², R¹³, R¹⁴, R¹⁵ canform together a condensed saturated or unsaturated 5 or 6 membered ring,optionally containing one or more heteroatoms belonging to groups 13-16of the Periodic Table of the Elements, said ring optionally bearing oneor more substituents; with the provisos that at least one of R¹², R¹³,R¹⁴, R¹⁵ and R¹⁶ is different from hydrogen atoms, and that no more thantwo of T², T³, T⁴, T⁵ and T⁶ are nitrogen atoms.
 19. A catalyst for thepolymerization of alpha-olefins obtainable by contacting: a) ametallocene compound of formula (I):

 wherein M is selected from the group consisting of zirconium, titaniumand hafnium; X, same or different, is a hydrogen atom, a halogen atom, aR, OR, OR′O, OSO₂CF₃, OCOR, SR, NR₂ or PR₂ group, wherein the Rsubstituents are linear or branched, saturated or unsaturatedC₁-C₂₀-alkyl, C₃-C₂₀-cycloalkyl, C₆-C₂₀-aryl, C₇-C₂₀-alkylaryl,C₇-C₂₀-arylalkyl radicals, optionally containing one or more heteroatomsbelonging to groups 13-17 of the Periodic Table of the Elements and theR′ substituent is a divalent radical selected from the group consistingof C₁-C₂₀-alkylidene, C₆-C₂₀-arylidene, C₇-C₂₀-alkylarylidene, andC₇-C₂₀-arylalkylidene; R¹ is a linear C₁-C₂-alkyl radical; R² is ahydrogen atom or a linear or branched, saturated or unsaturatedC₁-C₂₀-alkyl radical; R³ and R⁴, same or different, are hydrogen atomsor a linear or branched, saturated or unsaturated C₁-C₂₀-alkyl,C₃-C₂₀-cycloalkyl, C₆-C₂₀-aryl, C₇-C₂₀-alkylaryl, C₇-C₂₀-arylalkylradicals, optionally containing one or more heteroatoms belonging togroups 13-17 of the Periodic Table of the Elements; or they can formtogether a condensed saturated or unsaturated 5 or 6 membered ring,optionally containing one or more heteroatoms belonging to groups 13-16of the Periodic Table of the Elements, said ring optionally bearing oneor more substituents; R⁵ and R⁶, same or different, are hydrogen atomsor a linear or branched, saturated or unsaturated C₁-C₂₀-alkyl,C₃-C₂₀-cycloalkyl, C₆-C₂₀-aryl, C₇-C₂₀-alkylaryl, C₇-C₂₀-arylalkylradicals, optionally containing one or more heteroatoms belonging togroups 13-17 of the Periodic Table of the Elements; R⁷ and R⁸, same ordifferent, are hydrogen atoms or a linear or branched, saturated orunsaturated C₁-C₂₀-alkyl, C₃-C₂₀-cycloalkyl, C₆-C₂₀-aryl,C₇-C₂₀-alkylaryl, C₇-C₂₀-arylalkyl radicals, optionally containing oneor more heteroatoms belonging to groups 13-17 of the Periodic Table ofthe Elements; A, same or different, is a sulphur (S) atom or an oxygen(O) atom; Q is a radical of formula (II), (III) or (IV)) being bonded tothe indenyl at the position marked with the symbol *;

 wherein: T¹ is a sulphur (S) atom, an oxygen (O) atom or a NR group Rbeing defined as above; R⁹, R¹⁰ and R¹¹, same or different, are hydrogenatoms or a linear or branched, saturated or unsaturated C₁-C₂₀-alkyl,C₃-C₂₀-cycloalkyl, C₆-C₂₀-aryl, C₇-C₂₀-arylalkyl, C₇-C₂₀-arylalkylradicals, optionally containing one or more heteroatoms belonging togroups 13-17 of the Periodic Table of the Elements; or R⁹ and R¹⁰ canform together a condensed saturated or unsaturated 5 or 6 membered ring,optionally containing one or more heteroatoms belonging to groups 13-16of the Periodic Table of the Elements, said ring optionally bearing oneor more substituents; T², T³, T⁴, T⁵ and T⁶, same or different, arecarbon atoms (C) or nitrogen atoms (N); each of m¹, m², m³, m⁴ and m⁵ is0 when the correspondent T², T³, T⁴, T⁵ and T⁶ is a nitrogen atom and is1 when the correspondent T², T³, T⁴, T⁵ and T⁶ is a carbon atom; R¹²,R¹³, R¹⁴, R¹⁵ and R¹⁶, same or different, are hydrogen atoms or a linearor branched, saturated or unsaturated C₁-C₂₀-alkyl, C₃-C₂₀-cycloalkyl,C₆-C₂₀-aryl, C₇-C₂₀-alkylaryl, C₇-C₂₀-arylalkyl radicals, optionallycontaining one or more heteroatoms belonging to groups 13-17 of thePeriodic Table of the Elements; or two vicinal R¹², R¹³, R¹⁴, R¹⁵ canform together a condensed saturated or unsaturated 5 or 6 membered ring,optionally containing one or more heteroatoms belonging to groups 13-16of the Periodic Table of the Elements, said ring optionally bearing oneor more substituents; with the provisos that at least one of R¹², R¹³,R¹⁴, R¹⁵ and R¹⁶ is different from hydrogen atoms, and that no more thantwo of T², T³, T⁴, T⁵ and T⁶ are nitrogen atoms; b) an alumoxane or acompound that forms an alkylmetallocene cation; and c) optionally anorgano aluminum compound.
 20. A process for polymerizing one or morealpha-olefins of formula CH₂═CHZ, wherein Z is a hydrogen atom or aC₁-C₂₀ alkyl group, comprising the step of contacting underpolymerization conditions at least one of said aipha-olefins with acatalyst system obtained by contacting: a) a metallocene compound offormula (I):

 wherein M is selected from the group consisting of zirconium, titaniumand hafnium; X, same or different, is a hydrogen atom, a halogen atom, aR, OR, OR′O, OSO₂CF₃, OCOR, SR, NR₂ or PR₂ group, wherein the Rsubstituents are linear or branched, saturated or unsaturatedC₁-C₂₀-alkyl, C₃-C₂₀-cycloalkyl, C₆-C₂₀-aryl, C₇-C₂₀-alkylaryl,C₇-C₂₀-arylalkyl radicals, optionally containing one or more heteroatomsbelonging to groups 13-17 of the Periodic Table of the Elements and theR′ substituent is a divalent radical selected from the group consistingof C₁-C₂₀-alkylidene, C₆-C₂₀-arylidene, C₇-C₂₀-alkylarylidene, andC₇-C₂₀-arylalkylidene; R¹ is a linear C₁-C₂-alkyl radical R² is ahydrogen atom or a linear or branched, saturated or unsaturatedC₁-C₂₀-alkyl radical; R³ and R⁴, same or different, are hydrogen atomsor a linear or branched, saturated or unsaturated C₁-C₂₀-alkyl,C₃-C₂₀-cycloalkyl, C₆-C₂₀-aryl, C₇-C₂₀-alkylaryl, C₇-C₂₀-arylalkylradicals, optionally containing one or more heteroatoms belonging togroups 13-17 of the Periodic Table of the Elements; or they can formtogether a condensed saturated or unsaturated 5 or 6 membered ring,optionally containing one or more heteroatoms belonging to groups 13-16of the Periodic Table of the Elements, said ring optionally bearing oneor more substituents; R⁵ and R⁶, same or different, are hydrogen atomsor a linear or branched, saturated or unsaturated C₁-C₂₀-alkyl,C₃-C₂₀-cycloalkyl, C₆-C₂₀-aryl, C₇-C₂₀-alkylaryl, C₇-C₂₀-arylalkylradicals, optionally containing one or more heteroatoms belonging togroups 13-17 of the Periodic Table of the Elements; R⁷ and R⁸, same ordifferent, are hydrogen atoms or a linear or branched, saturated orunsaturated C₁-C₂₀-alkyl, C₃-C₂₀-cycloalkyl, C₆-C₂₀-aryl,C₇-C₂₀-alkylaryl, C₇-C₂₀-arylalkyl radicals, optionally containing oneor more heteroatoms belonging to groups 13-17 of the Periodic Table ofthe Elements; A, same or different, is a sulphur (S) atom or an oxygen(O) atom; Q is a radical of formula (II), (III) or (IV)) being bonded tothe indenyl at the position marked with the symbol *;

 wherein: T¹ is a sulphur (S) atom, an oxygen (O) atom or a NR group Rbeing defined as above; R⁹, R¹⁰ and R¹¹, same or different, are hydrogenatoms or a linear or branched, saturated or unsaturated C₁-C₂₀-alkyl,C₃-C₂₀-cycloalkyl, C₆-C₂₀-aryl, C₇-C₂₀-arylalkyl, C₇-C₂₀-arylalkylradicals, optionally containing one or more heteroatoms belonging togroups 13-17 of the Periodic Table of the Elements; or R⁹ and R¹⁰ canform together a condensed saturated or unsaturated 5 or 6 membered ring,optionally containing one or more heteroatoms belonging to groups 13-16of the Periodic Table of the Elements, said ring optionally bearing oneor more substituents; T², T³, T⁴, T⁵ and T⁶, same or different, arecarbon atoms (C) or nitrogen atoms (N); each of m¹, m², m³, m⁴ and m⁵ is0 when the correspondent T², T³, T⁴, T⁵ and T⁶ is a nitrogen atom and is1 when the correspondent T², T³, T⁴, T⁵ and T⁶ is a carbon atom; R¹²,R¹³, R¹⁴, R¹⁵ and R¹⁶, same or different, are hydrogen atoms or a linearor branched, saturated or unsaturated C₁-C₂₀-alkyl, C₃-C₂₀-cycloalkyl,C₆-C₂₀-aryl, C₇-C₂₀-alkylaryl, C₇-C₂₀-arylalkyl radicals, optionallycontaining one or more heteroatoms belonging to groups 13-17 of thePeriodic Table of the Elements; or two vicinal R¹², R¹³, R¹⁴, R¹⁵ canform together a condensed saturated or unsaturated 5 or 6 membered ring,optionally containing one or more heteroatoms belonging to groups 13-16of the Periodic Table of the Elements, said ring optionally bearing oneor more substituents; with the provisos that at least one of R¹², R¹³,R¹⁴, R¹⁵ and R¹⁶ is different from hydrogen atoms, and that no more thantwo of T², T³, T⁴, T⁵ and T⁶ are nitrogen atoms; b) at least onealumoxane or compounds that form an alkylmetallocene cation; and c)optionally an organo aluminum compound.
 21. The process according toclaim 20 wherein the alpha-olefins are selected from the groupconsisting of ethylene, propylene and 1-butene.
 22. The processaccording to claim 20 wherein propylene is copolymerized with ethyleneor higher alpha-olefins.
 23. The process according to claim 20 whereinethylene is copolymerized with higher alpha-olefins.